Glue and method of making the same.



UNITED STATES PATENT OFFICE.

FRANK G. PERKINS, OF SOUTH BEND, INDIANA; GERTRUDE S. PERKINS, EXECUTRIX OF SAID FRANK G. PERKINS, DECEASED, ASSIG-NOR TO PERKINS GLUE COMPANY,

A CORPORATION OF PENNSYLVANIA.

GLUE AND METHOD OF MAKING THE SAME.

No Drawing.

To all whom it may concern Be it known that I, FRANK G. PERKINS, a citizen of the United States, and a resident of South Bend, county of St. Joseph, and State of Indiana, have invented certain new and useful Improvements in Glue and Methods of Making the Same, of which the following is a specification.

My invention relates to improvements in glue and the method of making the same, and more particularly to the manufacture of glue from carbohydrates containing amylocellulose or its equivalent.

In the well known method of making a starch paste the solid is mixed with water enough, to make, after tumefying, a paste of such viscosity or density that it can be easily applied. This mixture is then subjected to heat to rupture or burst the cellulose walls and this cooking to a considerable degree supposedly reduces the cellulose to soluble starch, particularly in the presence of soluble starch already in solution. To increase the body or viscosity small amounts of ammonia have been added prior to or after heating. Such pastes have not the necessary relative tack, viscosity, cohesiveness and tenacity to spread and adhere properly when applied as wood glues. Such pastes in cooling also become extremely thick and jelly-like and are practically unsatisfactory for woodwork when originally made with water, or diluted after cooking, because water warps the wood .and delays drying and the pastes do not set hard enough and are not dense and elastic enough when dry. If more water is added in an attempt to make it more fluid, the paste becomes so weak and diluted that it has practically no power and would be Wholly unfit for most classes of work, especially wood joints.

Various objects of my invention are to provide a glue and a method of making the same from carbohydrates, which will not have the disadvantages just pointed out, but which will be exceptionally tenacious and powerful but still amply fluid for easy application, and which can be economically and easily produced.

A further object of my invention is to Specification of Letters Patent.

REISSUED Patented Mar. 19, 1912.

. Application filed November 2, 1908. Serial No. 460,737.

produce a glue which will have the great practical advantage that it may be practically used for the same purposes as the best animal glue, and possess certain great advantages of permanency to weather and temperature variations far superior to those of animal glue. As far as I am aware, such conditions have never been met by any prior adhesive made from a carbohydrate base.

A further important object of my invention is to produce an adhesiveor glue base which may be stored or sold in a dry state and which may then be prepared for use by mixing up with or without the use of heat. Such improvements are of great practical and industrial advantage and importance and have been much sought. To do this I first take a carbohydrate of the proper kind, and treat it with a reagent to decrease its water absorptive properties in the sense that to render fluid the finished glue, comparatively little water will have to be added and the final glue will not thereby become seriously diluted. The reagent I use I call a starch converting agent because it is believed it exercises, at least in part, a hydrolyzing or oxidizing or converting action similar to-that of the Well known starch converting agents many of which have been used to convert starch into soluble starch and dextrin. I may use any suitable starch converting agent but the action I produce is preferably much less complete since it is not my object to convert the starch wholly but only to effect its physical properties when put into solution or dissolved to form glue. The effect of this treatment is also that it decreases the viscosity of the glue produced with a given amount of water without detriment to its tack, quick adhesive properties and cohesion. As a base I prefer touse the starch secreted by the cassava plant, which has peculiar properties and advantages for this purpose. After being neared as above, the dried ma.- terial may be mixed with a small amount of water and with a solvent of amylo-cellulose, such as caustic alkali, and a lue produced the strength of which when dry is superior to the lateral strength of wood fiber. The prepared glue is very stable in its physitative change.

' plications which attend the use of an ad he's'ive which must, be cooked or warmed beforeuse, or kept warm during use, and is more powerful than that which results from 'the'treatment of starch in other ways. My

improved glue when made in its best form and properly applied will not only tear' away the wood at some pointin the wood joint produced by the use of this glue, but will tear away the wood at many points whether with or against the grain.

Further objects, advantages and" features will more clearly appear from the detailed description given below.

lncarrying out one embodiment of my invention I take the cassava carbohydrate or flour in dry form and add at least an equal weight of water. and heated to about 130 E, which is ,below the bursting temperature of the starch. Then I slowly add from 2% to 3% by weight (of the raw carbohydrate) of strong sulfuric acid. This may be considerably diluted if desired before it is added. The same is kept in continual agitation. The agitation preferably produced by thorough stirring is continued for from four to six hours after the acid has been added and then the acid may be neutralized by the addition of a small amount of caustic soda or similar alkali. The acid acts upon the starch or carbohydrate to decreaseits water absorptive properties. As the acid appears to remain unchanged in the batch, until neutralized, I believe itacts -cat-alytically to change the molecular condition of the carbohydrate without rendering it substantially soluble in the water. However, great care must'be exercised not to have the heat suficient or the acid in such quantity asto put thestarch or carbohydrate in solution. If the action of the acid and heat is carried too far the starch will be changed into dextrin, and will go into solution, and as such it would be lost to my process, as I utilize only the suspended material. Even this would cease to have the desired That. a large part, if not all, of the starch does not, in my improved process, go into solution, is shown by its settling upon stopthe agitation and by the weightand ana ysis of the product yielded. The batch therefore has not been converted into dex-.

trim Sulfuric and other acids as well as 1 other starch converting agents are stated to have acatalytic action afiecting the molecular state of amylose or its state of hydration.

This I believe to be promoted and equalized by prolonged agitation both together The batch is then agitated properties if the action were carried too far. f

with the action of heat, removing constitusuch other starches or starchy products may be used withmore or less success. Otherstarchy products from the cassava plant are foundto be more or less-adaptable and even other starchy products may be used with some little success but they do not produce glues so tenacious and are otherwise more or less undesirable. Some are affected by im-' purities.

The above proved process and the various steps therein may all he carried out at the factory.

In commercial use I preferably ship the dry material, obtained as above, to the conforms the first part of my iinsumer who carries out the second part of the process at the place where the glue is to be used, but if desired the first and second arts of my improved process may be carrie out w together.

In carrying out the remaining steps in the preparation of my improved glue, the dried base, obtained asabove, is mixed with about three parts or less by weight, (of. dried base) of water according to the strength of the joint and economy desired. The dried base does not materially go intosolution in the water unless heat is applied, but a liquid suspension is thereby formed which is agitated and treated with a solvent of cellulose, as, for example, an aqueous solution of caustic soda or potash alkaline to phenolthalien,

using if cold from six to ten per cent. of theweight of the dry base, of caustic soda or' its equivalent of caustic potash. The alkali, I believe, acts chemically to 'unite with one or more starch molecules and with the water to form a colloidal compound, The alkali is best added in the form of a solution of from 33% to 50% strength. Sodium and potassium hydrates are the most available and among the most powerful ofthe known solvents of the starch cellulose and are well adapted for most purposes. A

To take a specific example, a given quantity, say 200 lbs. of the drled amylaceous base was mixed with from to 300 lbs. of water (preferably 225 lbs. or less). After the mixture was thoroughly agitated, 20 lbs. of caustic soda was added in a concentrated solution of approximately one part alkali in one to two parts water.

This was added with extreme slowness, requiring v15 to 20 amylaceous base.

moisture of the air.

minutes for the 50 lbs. solution required.

During this time constant stirrlng was maintained in order to equalize and distribute the action of the caustic soda as fully as possible. When normal temperatures were used the result has not been obtained with less than 6 parts of NaOH per 100 parts of The result consists in what is called the passing over or coming across of the mixture and may be described as follows: During the earlier stages of the addition of the caustic in the above example, little difference in the appearance of the mass wasapparent. Soon, however, it became creamy and then more pasty and diflicult to stir. When about half the caustic soda had been added, there was faintly observable a minute mottled effect on the surface of the mass being stirred, and it gradually assumed a translucent porcelain-like appearance. If at this time a little of the mixture was squeezed between glass plates portions of the mixture were observed to be transparent and almostrinvisible. Other portions presented much the appearance of the original mixture of water and suspended particles of starch. As the addition of canstic soda proceeded accumulations of clearer matter occurred on the sides of the vessel and on parts of the stirrers and finally when the proper amount of caustic had been added, the entire mass passed over or came across, being converted from a mixture of suspended starch and water containing caustic to a homogeneous colloidal compound of starch, caustic and water. A little excess of caustic was preferably added to prevent decomposition of the compounds by the carbonic acid or As much as fourteen per cent. NaOH, or the equivalent of other caustic may be used, leaving some free caustic in the prepared glue. The word compound is here used in the more modern chemical sense of matter connected within the limits of some quantitative relation to produce a definitely recognizable product having certain definite physical characteristics. It is found that temperature affects the amount of caustic required to-produce this result and it is believed that as temperature affects the polymerizing or uniting power of the starch molecules, one with another, so it affects the ability of a smaller quantity of caustic to satisfy or bring across a given quantity of starch. It is found that at successively increasing temperatures one is enabled to br ng across the mixture with successively decreasing proportions of caustic.

As previously stated, when ordinary starch is heated with water, it absorbs enormous quantities of water, and if only two or three parts of water are used becomesof a stiff jelly-1ike form which must be very much diluted before it will be practically workable. I find, however, that using my improved glue base and method of mixing the same, this water absorbing power can be greatly reduced and can be regulated, although the mixing is done with the same proportions of alkali and carbohydrate or else the same temperature, which have hitherto produced unworkable-jellies or weakly adhesive pastes or mucilages. And by the use of cassava starch in particular, results can be secured entirely different from those hitherto produced, as stated by others, preferably with corn. Thus, by proper adjustment of conditions of mixing I am able to produce this glue even with certain grades of untreated cassava carbohydrate and with other starches and conversion products (starchy carbohydrates). The preliminary treatment, however, substantially reduces the absorption of 'water by the starch and prevents it from becoming jelly-like and tough when afterward treated either with the water as above indicated or with the alkali, or both.

In the second part of my improved process, less than about three parts of water by weight to one part of the dry material are used and after adding the solvent it is found that even with such a small amount of water, the batch will assume a semi-fluid consistency much superior to that ordinarily obtained by the use of water alone and will not become jelly-like and tough as in former processes. The alkali added acts, I believe, to dissolve more or less of the cellulose and carbohydrate, uniting with the same and with the water and forming a glue of very tenacious properties. The ry carbohydrate is mixed with the water with a carefully regulated heat, if any. The action of heat replaces the action of a portion of the caustic in transforming the glue base, as explained above. By the preliminary treatment in reducing the water absorbing power of the carbohydrate, a very concentrated mixture with water may be obtained.

Experiments indicate that after the carbohydrate base has been treated in accordance with the first step of my process, the proportion of amylo-cellulose in the carbohydrate granule has been increased. believe this increase in the percentage or proportion of the amylo-cellulose in the carbohydrate allows of the same to be changed into a good glue with very much less water than would otherwise be required. One way which has been found quite satisfactory for determining when the action of the acid or its equivalent, and the agitation, have been carried far enough in the first step, is as follows:

When the carbohydrate glue base which has been dried hasbeen boiled for ten minutes with dry live steam at 100 lbs. pressure with 9 parts of water and tested for viscosity while hot, it showed a'viscosity bethat of cold water.

Inspecific examples tried, the carbohydrate base, subjected to the. above test, has shown viscositiesbetween that of cold 'water and three times thatof cold water, but a product showing about two times cosity of water iSpreferTed.

The carbohydrate glue base in the preferred form retains substantially unchanged the vis the size and general form of particle as]. viewed under the microscope when treated may be traced to the proper proportioning of viscosity, cohesion and adhesion, together with the peculiar chemical action which caustic loosely combined or free in the glue as applied, exerts on the cellulose which it in-turn combines with, in making the joint 'to form alkali metal carbonate, bicarbonate and acetate. I believe this proper proportioning is due to the partial change of the integument and the proper proportioning'of the amylo-cellulose and'the granulose (or the proper mean polymerization) when onse' united with the caustic and water. quently, I believe that to obtain the best results it is necessary to abstain from reduc ing the cellulose'to true soluble'starch, and

- that sufficient cellulose must be left to make the glue amply tenacious. Therefore, the action of the acid and alkali should not be carried so far nor the temperaturebe so high as to destroy all the cellulose and impair its strength by'changing it into'soluble starchand the starch into sugar or dextrin. Also, in actual practice I havegfound that a good glue is produced by treating the basewith the chemicals to reduce the water absorbing power to a point where the base if 'mixed with from 2 to 3 parts of water and subjected to heat of 170 F. would result in a s rupy condition instead of'a thick jelly-1i emass.

ing a strength similar to threads of animal Practically all the water must be later removed that goes into the glue solution' and is applied .to\the joints, hence an increase of water in the glue solution involves changes in drying methods, or in tween that of cold water and three times.

practically unaflected by natural humidity I find that by such suitable, treatment under my process it is possible to produce from the base long filaments hav-- '60 glue.

time:

sin time, or in risks of injury to the ma: terial due to warping by the extra water,

all of very serious consequence. The diluted -or adulterated pastes hitherto made from the natural carbohydrates in the manner explained before are unfit for many classes of work and especially wood joint work, since they contain so much water or adulterants that it takes the'joints very long to dry or when they do becoine dry there is so little binding material left that only a very weak bond is obtained. Thus it is of the greatest importance and value to produce a concentrated glue solution ready for applicationf which parallels the animal glue solutions now employed industrially,-in respect to water contents and physical properties in,

application, and is equal or superior as to strength and permanency.

Certain advantages of myimproved process may be obtained to some extent even although other materials be mixed with the .amylaoeous material to form the glue base.-

In the preferred form described 'myimproved glue is transparent and free ,from odor, and is very stableatter mixing for use, it is instantly adhesive to, clean surfaces, its I cohesion is very great but not suflicient to overcome its adhesion and its viscosity is lasting and low enough to permit ready application, but so proportioned to its cohesion that it is capable of bfingapplied by ma-- chinery' like hide glue, but still very long tough fibers are produced if freshly joined surfaces are separated. I have found that, owing to the breakage of these filaments crackle like electric sparks.

My glue'will produce joints which are and which are unaffected by'prolonged dry heat. In the preferred form it forms a joint with wood or other cellulosic material, which joint is distinguished'from ordinary muci lages', sizes and pastes by the fact that it consists of the following-layers in the order named, unaltered cellulosic material, cellulosic material altered by caustic, tough amylaceous material altered by caustic,- cellulosicmaterial' altered by caustic and unaltered cellulose. This joint can probably be distinguished wherever found, by theshading of the above layers into one another when stained with idodin and examined under the microscope and by other tests. v(lrlued 120 up: panels have been laced behindaradiator for 18months wit out cracking-or separating of the glue, joint; These features make my glue especially advantageous for purposes in which other vegetable glues are 125 practically useless.

Although I havedescribed m impr'ove ments in great-detail and with much par--3- ticularity and have men 'oned particular compounds "which I prefe to use, I30

quick separation of such'surfaces produces a it to be understood that I do not limit myself to such details and compounds, except as clearly specified in the appended claims, as many modifications and substitutes may be found; but,

hydrate with water and a starch converting.

agent whereby the polymerization of the carbohydrate is altered to a point such that when dissolved it will form a viscous semifluid unjellified product adapted to be applied by machinery.

2. The process of making wood glue which consists in taking suitable carbohydrate material and properly proportioning the viscosity, cohesiveness and adhesiveness of the carbohydrate material resulting when it is dissolved to form glue applicable by machinery and then dissolving the carbohydrate material with a solvent of cellulose to 'put it into solution to form glue.

3. The process at making. a glue. base which consists in agitating a starchy carbo hydrate with water and a starch converting agent to decrease the water absorptive properties of the carbohydrate to properly pro portion the viscosity, adhesiveness and cor hesiveness resulting when the base is dis.- solved to form glue properly for theapplication of the glue by machinery.

4. The process of making a glue base which consists in agitating a starchy carbohydrate with water and suitable chemicals below the bursting temperature of the starch to proportion the viscosity, adhesiveness: and cohesiveness resulting when the base is dissolved to form glue applicable by machinery.

5. In the making of adhesives, treating cassava flour with substantially an equal weight of water, heating the same to about 130 F. and adding about 2% or 3% by weight of strong acid slowly and with a tetion, without rendering the flour materlally soluble in water, then neutralizing the acid with an alkali after from 4: to 6 hours agitation.

6. In the making of a glue base, treating amylaceous material with a reagent to decrease its water absorptive properties, leaving a material portion of amylaceous material in the product insoluble in water.

7. In the making of adhesives, treating a suitable carbohydrate with water and a digesting-agent without rendering the carbohydrate materially soluble in water, to decrease the water absorptive properties of the carbohydrate.

8. A glue base characterized by the facts that it is prepared from starchy material, retains substantially unchanged the size and general form of particle when treated with cold water, and produces opalescent cloudy solutions with water at 200 F.

9. The process of making glue which consists in treating starch below the bursting temperature of the starch, with a digesting agent such as caustic and water until the material assumes a viscous semi-fluid consistency adapted to be applied by machinery.

10. The process of making glue which consists in dissolving cassava carbohydrate in caustic alkali until a glue is formed as distinguished from mucilages, sizes and pastes- 11. The process of making a glue, which consists in treating a starchy carbohydrate with caustic alkali, and water, to dissolve the carbohydrate, the total amount of water used being about 3 parts or less by weight of the carbohydrate, the amount of caustic alkali used, calculated as NaOH being about 10% or less by weight cat the carbohydrate so that a wood glue is formed, as distinguished from mucilages, sizes and paste.

12. The process of making a glue, which consists in mixing starch with water and caustic alkali to dissolve the carbohydrate, the amount of water used being about 3 parts or less by weight of dry carbohydrate so that a wood glue is formed, as distinguished irom inucilages, sizes and paste.

13. The process of making a wood glue which consists in treating a suitable starchy product a material portion of which is sub stantially insoluble in water with a solvent of cellulose and about 3. parts or less by weight of water, to produce a glue having adhesive powers substantially as great as those of good animal lue. 1

14. In the making or glue, treating a suitable starchy product with about three parts or less by weight of water and adding a solution of caustic soda or other equivalent alkali using about 10% or less by weight of the caustic soda or its equivalent of other alkali to dissolve the product.

15. In the process of making wood glue, the combination of the followi steps, agitating a starchy carbohydrate with a digesting agent to decrease its water absorptive roperties without converting the batch into entrin, and then substantially dissolving the product thus produced with about three parts or less of water until the resulting product has a consistency such that it is applicable to glue up veneers.

16. In the process of making. wood glue, agitating a starchy carbohydrate with a di gesting agent until a sample of the material taken from the batch and dissolved will show a viscosity, adhesiveness and cohesiveness substantially equal to animal glue.

17. The process of making wood glue which consists in agitating starch with a digesting agent to decrease its water absorp- I 19. Inythe process of making wood glue,

the combination of the following steps, agitating a cassava carbohydrate with adigesting agent to decrease its water absorptive properties without rendering the carbohydrate materially soluble in cold water and then putting the product thus produced into a solution containing about three parts or less by weight of water to produce a glue for application.

20. The process of making glue, which consists in agitating a starchy carbohydrate with water and a digesting agent to reduce the water absorptive properties of the carbo-- hydrate without rendering it materially soluble in water, then mixing the carbohydrate with water and caustic alkali, the

amountof water used being about three parts or less by weight of dry carbohydrate,

the amount of causticused being about 10% or less by weight of dry carbohydrate, to dissolve the carbohydrate. to form the glue as distinguished from mucilages, sizes and paste.

21. The improved glue process which con: A 40 sists in treating cassava carbohydrate with substantially an equal weight of water, heating the same to about 130 F,, adding from 2% to 3% by weight of an acid, slowly, and during agitation, neutralizing the batch with an alkali after from 4 to 6 hours agitation, then cooling and dryingjthe batch, then adding from 1 to 3 parts'by weight of water, and then while being agitated treating the same with a, solution of a caustic alkali using about 10% or less by weight of thedry alkali and applying the resulting product to surfaces with which the caustic,

is adapted to combine and forming a joint between said surfaces.

22. In the making of adhesives, treating a suitable starchy carbohydrate insoluble in water with water with a reagent to decrease its water absorptive properties but without rendering the carbohydrate materially solu-- ble in Water, then allowing the batch to dry,

then treating the same with water and a solvent of cellulose such as caustic alkali to form glue.

23. In the making of adhesives, treating a suitable starchy carbohydrate with an agent having 'an acid reaction without rendering the carbohydrate materially soluble in water, to decrease the water absorptive properties of the carbohydrate and then. treating the carbohydrate'with asolvent of cellulose, thus proportioning the viscosity, ailhesiveness and cohesiveness of the final g ue. 24. A carbohydrate base for making glue composed of suit-able carbohydrate which when mixed with about 3 parts or less by weight of water and a solvent of cellulose will form a semi fluid mass having substantially the adhesive properties of animal glue.

25. A base for making glue as distinguished from mucilages, sizes and pastes, embracing treated amylaceous grains substantially insoluble in water and the outer so-called amylo-cellulose coating of which insoluble grains has been partially but not entirely converted. I

26. A base for making glue composed of a starchy carbohydrate or its equivalent which when boiled*for 10 minutes with dry hot steam at 100 pounds pressure with nine parts of water and tested for viscosity while hot will show a viscosity between that of cold water and three times that of cold water. p

i 27. A base for glue as distinguished'from 5 mucilagcs, pastes and sizes, comprisingtreated cassava amylaceous grains in which the proportion of so-called cellulose is greater than in the natural material from Which the base is derived.

28. A glue comprising cassava carbohydrate rendered semi-fluid by digestion and having substantially the properties'of animal glue.

29. A glue comprising chiefly starch dissolved by a digesting agent alkaline to phenolphthalien and in about3 parts or less by weight of water.

30. A Woodand fiber glue formed of a starchy -carbohydrate or its equivalent by union therewith of about 3 partsor less by weight of Water and alkali metal hydroxid.

31. A wood and fiber glue containing amylaceous material as a base dissolved without acid in about three parts of water or less, and being viscous, semi-fluid and unjellified. 1

32. A glue as distinguished from mucilages, sizes and pastes containing a starchy carbohydrate base substantially insoluble in' water and dissolved by caustic and containing free caustic.

38. A glue consisting of a vegetable carbohydrate base substantially insoluble in water and dissolved by water and caustic 1 soda alkali, the amount of water being about three parts or less by weight of dry carbohydrate and the amount ofi caustic present being about 10% or less by weight of the dry carbohydrate.

34. A glue consisting of a vegetable carbohydrate base substantially insoluble in .Water and dissolved by caustic alkali, the amount of Water being about three parts or less by Weight of dry carbohydrate.

35. A glue containing a starchy carbohydrate base dissolved by a solvent of cellulose and Water, the amount of water in the glue being about three parts or less by weight of dry carbohydrate.

36. A glue as distinguished from mucilages, sizes and pastes, consisting chiefly of a starchy carbohydrate base substantially insoluble in water and dissolved, by a solvent of cellulose.

37. A glue composed of a starchy carbohydrate base and a solvent of cellulose and having such a character that it will be substantially unaffected by the natural humidity and having substantially as good adhering qualities as thebest animal glue.

38. The process ofmaking a wood gluev which consists in suspending a glue base containing amylaceous matter insoluble in water in about three parts or less by weight of water and treating the base with an alkali properly proportioned substantially as described to produce a glue having a lasting viscosity to flow through pipes and the adhesiveness of animal glue.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

FRANK G. PERKINS. Witnesses GORHAM Cnoser, EDWIN SEGER. 

